Motor-driven reciprocating saw unit



Feb. 9, 1954 H. M. OLSON v 2,668,567

MOTOR-DRIVEN RECIPROCATING SAW UNIT Filed May 31, 1949 2 Sheets-Sheet l \uvzm'oa H LLY M.OLSON ATTQ nnsvs' Feb. 9, 1954 OLSON 2,668,567

MOTOR-DRIVEN RECIPROCATING SAW UNIT Filed May 31, 1949 2 Sheets-Sheet 2 FIG. 5.

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l MMQ Z 28 ATTORNEYS Patented Feb. 9, 1954 UNITED STATES PATENT OFFICE MOTOR-DRIVEN RECIPROCATIN G SAW UNIT Holly M. Olson, Muskegon, Mich.

Application May 31, 1949, Serial No. 96,308

Claims. 1

This invention relates to a motor driven saw unit, and more generally, a, motor driven reciprocating drive of a processing member, of which a saw is one example, it being understood that for the saw which is moved back and forth in the direction of its length, other processing members as a substitute therefor may be used without changing or departing from the invention.

It is an object and purpose to provide a very compact, light weight processing unit which, as I have built the invention, is in connection with a saw, and drives the saw very rapidly by direct connection to an electric motor, and in practice by direct connection to an electric motor of a hand drill in which a drill is detachably connected by a chuck or other similar means with the shaft of the motor, which in turn is housed within a housing having a hand grip. By means of the drill holes may be very rapidly drilled at substantially any angle desired, the hand engageable drilling unit being directed by the hands of the operator so as to drill a. hole at any place accessible by the drill.

With my invention a particularly simple, novel and practical mechanism is used for converting the rotary movement of the electric motor of such drill unit to a reciprocating movement, the drill connecting chuck of the motor driven drill unit being readily attached to a driven shaft forming a part of the reciprocating unit, and with which a saw or other processing member or tool may be connected for sawing or other operations.

It is a further object of the invention to provide a novel, very simple and practical and durable mechanism for converting the rotary to the reciprocating movement and which will work effectively at very high speeds of rotation of the motor. Such motors may drive at 1800 R. P. M. or at twice such speed of rotation or more; and with my invention, with each rotation of the motor shaft, a complete reciprocation of the saw or other processing tool takes place.

An understanding of the invention may be had from the following description, taken in connection with the accompanying drawing, in which:

Fig. 1 is an elevation showing the motor saw unit of my invention operatively attached to the spindle of a motor driven drill unit.

Fig. 2 is a similar side elevation of the saw unit of my invention and the manner in which it is used and at two extreme positions of the saw unit, one at the beginning of a sawing operation of a board, and the other the position when the board is being sawed entirely through it.

Fig. 3 is a somewhat enlarged full size side elevation, with the cover plate at one side of the unit housing removed, and with some parts shown in vertical section for better disclosure.

Fig. 4 is a fragmentary side elevation and partia1 section of the change direction mechanism by means of which the rotary is converted to the reciprocatory movement.

Fig. 5 is a horizontal section substantially on the plane of line 5-5 of Fig. 3 looking downwardly.

Fig. 6 is a transverse vertical section substantially on the plane of line 66 of Fig. 5.

Fig. 7 is a similar transverse vertical section, on the plane of line of Fig. 3, and

Fig. 8 is a perspective view of an element of th structure, including the motor driven shaft and the head thereon which operates the reciprocating mechanism, together with fan vanes for blowing air for the purpose of removing sawdust during a sawing operation.

Like reference characters refer to like parts in the different figures of the drawings.

In the structure of the sawing unit illustrated, a housing is used, having vertical side I, a, vertical back 2 through which air passing openings 20 are made, a horizontal top 3 and a downwardly or forwardly inclined front 4 at the lower end portion of which a lug 5 extends in a forward direction. Such parts of the housing are integral and from the back 2 a bearing boss 6 extends to the rear, while at the front of the inclined front member 4 a thickened boss I is integrally cast for the attachment of a knob 8, by means of a short shaft 8a extending therefrom downwardly into the boss 1, and secured by a set screw (Fig. 5). The other side of the housing is open and in practice is closed by a second vertical, removable side 9 which is detachably secured in place by screws, as shown.

A horizontal shaft l0 passes through the boss 6 and is mounted by means of suitable bearings for rotation. Within the housing, at the front side of the rear member 2 of such housing a head is secured which, as best shown in Fig. 8, comprises two diametrically opposed relatively heavy arms I I cast integral with a central hub l2. From the hub I2, at opposite sides thereof and between the arms I I, vanes I3 extend outwardly which are positioned in planes inclined to the axis of the shaft ID. In each of the arms II at its inner side an opening or recess I4 is drilled or otherwise provided. The axes of such openings are inclined to the axis of the shaft [0 (Fig. 3), and at their outer end portions are enlarged in diameter as shown. The shaft I0 is adapted, where it extends back of the boss 6, to be detachably connected to the drill carrying shaft of a motor driven hand drill l5, the chuck [6 which receives the end of the drill spindle being adapted to be detachably secured to the projecting rear end of the shaft 10. Thus the head at the inner end of the shaft I0 is driven at the same speed of rotation as the armature of the motor.

The open under side of the housing is closed in the main by an elongated horizontal bar or plate I! which, together with a guard 18 shaped as shown in Fig. 3, and a saw guide fixture I9, is secured by means of screws 20 and 2| in fixed relation to the housing. The ends of the guard lie underneath the bar I1 and at the rear ends of the guard and bar screws 20 pass upwardly through into the rear ends 2 of the housing; Thefront end 3 of the guard" I 8 is underneath the; front end portion of the bar W, the saw guide-fixture I9 is underneath it, and screws 2! (Figs. and 7) pass downwardly through the lug 5 into the meme ber 19 for securing the parts together, Thefront end portion of the bar [1 substantially at'the front of the lug 5 is bent to extenddownwardly as at Ila and then bent in an arc and extend as a terminal section l'ib which "is inclined" to the horizontal as shown in Fig. 3.

The parts Fla and Ill) of the bar I! have an openi g Jr-Slot V22 thereinpositioned generally in a vertical plane, the slot being closed at both ends. Thebal' if! from its, rear end, forwardly for the major portion of tis length, is slotted midway between, its. side edges to. provide an'elongated slot 23. The sawguide fixture i9, (Fig.7) .is slotted at. its under side upwardly. from front to rear, asindicated at. 26, and two screws 25, which in the saw unit preferably are of. brass-or any other equivalent. metal which will.not. scuff when Asawcal'riaee 27, substantially in theform ofa p r rectangular in cross section, is slidably mounted on the bar ILhaving opposed guide slots in its sides, (Fig, 6) .the carriage being movable backand forth in the slot v23. .At thefrontand rear ends of the carriage 2i, downwardly extendingjlues are cast which are. slotted upwardly. between 'thflrsidesfor' the receptionofthe rear portionofa saw blade. 28, releasably clamped in place by screws zii. The. saw blade 28 extends forwardly through a suitable slot in the guard I 8,, between the adjacent ends of .the screws and through the slot .22 in the frontend portion of the bar H as shown in F 4-. In the upper side and near. the rear end Qfthe carriage-21 a vertical recess 38, is drilled.

' Thejdriving mechanism between-therotatable h adat'fthe inner end of th shaft. [0. and the reciprocable carria e 21 includes a cker,- wh c s moun ed to rock about the horizontal axisof two aligned supportin and bearingpingfil (Fig. mounted on nd. ex ndingthroueh he fixed side I and the remoyableside 9 ofthehousing, at their inner ends extending partlyinto,.the.chainber within'the housing. The rockermember. in? cludesahorizontal bar" 32,, substantially square in r s section, with openin sat itsendste re: ceive the projecting ends of thefixed pins 31, and a downwardly extending lug.33 integral with the bar'32. A bentrrod having a straight section-.34 passesidownwardly through the bar32 and the lug '33. Between its ends itihas a groove. around it 'tFig. 6), and a.pin 35is driven through the lug 34 seating partly in thegroove and partly ina groove in such lug so asto lock the straight section 34 against endwise movement, but permitting free turning or rocking movement thereof. :The lower end of the section 34, below thelower end f the his 33, is re uced in diameterand termi nate in a cylindrical head or ball 36 whichis-re ceived in ,the recess 30 of the carriage Z'l;

Abovethe upper side of bar.32 therodisment into .a substantially semi-circular shape a at 3L. an hence cont nuedfina .ewrselrbent 5 i efimkotwhi hisa reduced sec:

tion terminating, in a;secondzspherioali'head or ball 39 adaptedto enter aselected recess I4 in outward -recess" Hi or in the other or inner remess; M;

With the structure as described, and with the shaft. .lfirdriyen at high speedofrotation bythe motor. of. a hand mot r. drill; unit he s aight sectionf 31; of the. bent. rod is rocked back and forth about its longitudinal axis and simultaneously the bar'32'with the'depending lug 33 rocked back and; forth about; the. horizontal axis ,of the pins'3la With each-'rotaticn of the shaft 1 fl the carriage 217 and the saw: blade 28 fixed thereto make a complete reciprocation. Thus with the shaft driven-M3600 R: the saw blade- 38 make 3600-" complete reciprocation =per' minute. The saw blade at its outer" end always projects in" all positionsof it beyond the part 1-7 a at the front portion of" thecarriage supporting; and guide bar 'I I; and at its' farthest front position the saw= unit; 'whiclr' in Fig." -3"is shown-in full size, projects asufficient-distance so thatall lumber ofa standard-oneinch thicknessor less may-be sawed through.

In the use of 'the motor=saw unit (Fig; 2-)=the rearwardly anddownwardly inclined terminal section l 'ib of the-bar i 7 rides-as: indicated at. 45. The board-maybe started as to the-sawing therein either at a free edge of itorbetween-edgesas indicateddn Fig. 2 theunit being turned counterclockwise-from its full lineposition-in Figi 2, to the vdash line position. In suchdash .line posi tion, "the-motor. unit supportedat the bend betweenthe two sections I ia-and Ilibp 'The operator may. grasp theknob 8-,: for-example with his. ieftshand; and thehand-letat' therean endof the motor housing: ifit'withcthei others-hands and guide the saws-in any...directiorr;wanted either: in straight; onourvedzlines. lit-1 apparent. that: not only. may: 1 a board t .be sawed through from-its uppen-to its, lower-side; but;- slots or.-.kerfs .of 5 pm:- selected rdepths may. be. out-:from' the upper: side downwardly any; selected-distances. wanted,- with the bottoms of kerfseshortgofrthezunderzside Qfth board-i.

The hea in nortienssofcthewarts; ilbsandtof the bend; be weenjit and the section: i-lazmayabe hardened of ms with wearineacsurfacesrior memhersiasrwante swi hstandxthewear;which akes tplacezup nwestensive use.vv The l'a-f j;il?0r ta ionmf :th van s I 3-:onvtheehub J i 230i there: tating head causes a current of air, drawn throuehtheop ninesrta iinztherearrend 2 ofthe fli ertmbeforcedeutwar yhrcuehth 23 in the p ate: ll ndrblow; amma drawn .unward y'; to. the; upper urface e o the tion of heat so that the apparatus is exceptionally durable because of its extreme simplicity of structure. In operation in the size shown in full scale in Fig. 3, at which the unit has been constructed .and used, it has not only operated in an exceptionally satisfactory manner, but perfectly.

It is of course to be understood that in a larger size, the saw blade 28 will be longer and extend out farther to the front for use in sawing standard lumber two inches in thickness or between one and two inches in thickness. It is a unit which is adapted to be used with motor driven hand drills which are very largely used. And while the saw has been described as a wood saw, metal may be also sawed by using a suitable hack saw for such purpose.

As earlier mentioned, the invention has been embodied using a saw as the tool to be operated thereby. It is apparent however that such conversion from rotary to reciprocatory movement may be useful in a great many other ways than in sawing, and the invention is not to be limited solely to sawing devices as disclosed, but is to be considered comprehensive of all forms of structure coming within the scope of the claims hereto appended.

I claim:

1. In a structure as described, a supporting housing having spaced parallel sides, a rocker member located between and mounted on said sides for rocking movement, a rod rotatively mounted on and extending through said rocker member at right angles to the rocking axis of said member, a shaft rotatively mounted on the housing and extending toward the rocker member, a head on said shaft having a recess in the side thereof adjacent the rocker member, said recess located outwardly from the center of said shaft, said rod at one end thereof including a laterally bent section extending toward said head and terminating in a ball located in said recess, a carriage, supporting and guide means for said carriage connected with sid supporting housing for supporting and guiding said carriage in back and forth reciprocating movements, and a universal joint connection between the opposite end of the rod and said carriage.

2. In a structure as described, a housing having a generally horizontal top, a vertical side, a vertical back and a generally vertical front, said top, back and front being integral, a second side parallel to the first side having means for detachable connection to close the housing except at its bottom, and said housing at its lower front portion having a forwardly extending lug integral therewith, a longitudinally slotted plate secured to and closing the lower side of the housing, a rotatable shaft mounted on and extending through said back, a head within the housing connected to the inner end of the shaft, a carriage slidably mounted for back and forth movements on said plate, a horizontally disposed rocker member extending between sides of the housing, means for mounting said rocker to rock about a horizontal axis, a rod having a straight section rotatively mounted on and extending downwardly through said rocker member, ball and socket connections between the lower end of said rod and the carriage, said rod at its upper portion having an integral generally inverted U- shaped portion extending rearwardly therefrom and terminating in a terminal section located at an acute angle to the axis of said shaft, said terminal section at its free end having an integral ball and said head having a recess to receive said 6 ball, said recess being disposed at an acute angle to the axis of the shaft and located a distance outward from said axis.

3. A structure as defined in claim. 2, said back having air passage openings therethrough and said head having air current inducing vanes thereon extending outwardly from and rotatable with the head for drawing air through said passages and forcing it outwardly at the lower front portion of said housing.

4. In a structure as described a housing having a top, front and rear ends and spaced Vertical sides, means for detachably connecting one of said sides in place, a driven shaft rotatably mounted on and extending through the back of the housing, a supporting guide plate detachably secured at the under side of the housing across the open bottom thereof, a carriage mounted on said plate for back and forth movements thereon, a head at the inner end of said shaft, operative connections between said head and carriage, including a member mounted between the sides of the housing for rocking movement about a horizontal axis, and a bent rod passing through the rocking member and mounted to turn about an axis at right angles to the axis of rocking of said member, and universal joint connections at the ends of the rod with said head and carriage, for reciprocating the carriage one complete reciprocation with each rotation of the shaft and attached head.

5. In a structure as described, a supporting housing having spaced parallel sides, a rocker member located between and mounted on said sides for rocking movement, a rod rotatively mounted on and extending through said rocker member at right angles to the rocking axis of said member, a shaft rotatively mounted on the housing and extending toward the rocker member, a head on said shaft having a recess in the side thereof adjacent the rocker member, said recess being located outwardly from the center of said shaft, said rod at one end thereof including a laterally bent section extending toward said head and terminating in a ball located in said recess, a carriage, supporting and guide means for said carriage connected with said supporting housing for supporting and guiding said carriage in back and forth reciprocating movements, a universal joint connection between the opposite end of the rod and said carriage, air propelling vanes connected with said rotatable head for forcing air in a downward direction, and a plate closing the lower side of said housing, said plate having an air passing opening therethrough.

HOLLY M. OLSON.

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